자료유형  

 학위논문

Control Number  

0016933647

International Standard Book Number  

9798379565237

Dewey Decimal Classification Number  

576

Main Entry-Personal Name  

Carlson, Avery Lachlann.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Michigan., 2023

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Physical Description  

1 online resource(244 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 84-12, Section: B.

General Note  

Advisor: Daigger, Glen T.;Love, Nancy G.

Dissertation Note  

Thesis (Ph.D.)--University of Michigan, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Restrictions on Access Note  

This item must not be added to any third party search indexes.

Summary, Etc.  

요약Biological nutrient removal (BNR) wastewater treatment processes are an established field of research in environmental engineering. Harnessing knowledge on carbon, nitrogen, and phosphorus removal pathways has been effective in remediating water bodies around the world. Membrane treatment technologies are an evolving subsection of BNR wastewater treatment, including membrane bioreactors (MBRs) and membrane aerated biofilm reactors (MABRs). The former configuration processes wastewater through conventional suspended growth, but performs liquid-solid separation on mixed liquor biomass. The latter directs aerates a nitrifying biofilm through a gas-permeable membrane. Advanced chemical and biomolecular methods, beyond what is standard at wastewater plant laboratories, can be used to trouble-shoot existing plant issues, provide feasibility for technologies in the development stage, or to provide more insight on fundamental biological metabolisms driving BNR at membrane wastewater plants.In this dissertation, chemical and biomolecular tools were used to uncover drivers of sudden onset fouling preventing permeability at the Traverse City Regional Wastewater Treatment Plant MBR. Early observations hypothesized fouling occurred due to a gram-positive bacterium captured on microscopic evaluations of mixed liquor. Illumina 16s rRNA sequencing of laboratory isolates, and fluorescent in situ hybridization were used to identify the organisms as Staphylococcus; however relative abundance in mixed liquor samples from normal and disrupted operation were statistically insignificant. Constrained ordination plotting of sequence variance with plant metadata suggested fouling correlated with calcium concentrations in the plants mixed liquor. It was hypothesized and supported through multivariate statistical analysis, and estimation of specific resistance to filtration values, that a calcium-intermediated polymer bridging mechanism is one major contributor to fouling and permeability disruptions in the plant's MBR.Computer simulation was later used to assess the feasibility of BNR in a proposed hybrid MABR design. A highly-efficient nitrifying biofilm coupled with a large anoxic suspended growth zone demonstrated strategic advantages over conventional activated sludge configurations. Results show successful removal of total inorganic nitrogen and orthophosphate below common permit limits, and carbon capture at solids retention times (SRTs) of 4.0 days or lower. To assess the veracity of process models, a series of batch reactors were constructed to treat domestic wastewater. Experimental measurements calculated oxidized carbon of side-by-side aerobic and anoxic treatment systems. At longer SRTs, a divergent response pattern was observed for anoxic hydrolysis compared to aerobic. Results suggest that a fraction of influent particulate and/or colloidal organic matter was hydrolyzed in the aerobic culture, but not in the anoxic culture with nitrate as the terminal electron acceptor.Anoxic hydrolysis reduced volatile fatty acid (VFA) production, and ultimately the orthophosphate release rate of denitrifying phosphorus-accumulating organisms. Stoichiometric evaluation suggested a lower anoxic P/O ratio (0.90 versus 1.7 for the aerobic reactor) suggesting less efficient oxidation of anaerobically-stored polyhydroxybutyrate. Furthermore, metagenomic sequencing revealed the presence of respiratory (nar) and periplasmic (nap) nitrate reductase in the anoxic bacterial population. Periplasmic nitrate reductase is considered thermodynamically unfavorable, which may factor into less efficient intracellular energy generation.The results of this dissertation show how interactions between nutrients and biology can impact wastewater treatment performance in various designed environments. Ultimately, this research serves to provide vital information on how to analyze designed membrane treatment plants in operation, how to optimize resources, and further reduce nutrients beyond what is available with conventional activated sludge treatment systems.

Subject Added Entry-Topical Term  

Microbiology.

Subject Added Entry-Topical Term  

Environmental engineering.

Subject Added Entry-Topical Term  

Water resources management.

Index Term-Uncontrolled  

Biological nutrient removal

Index Term-Uncontrolled  

Membrane bioreactor

Index Term-Uncontrolled  

Membrane aerated biofilm reactor

Index Term-Uncontrolled  

Wastewater treatment systems

Added Entry-Corporate Name  

University of Michigan Environmental Engineering

Host Item Entry  

Dissertations Abstracts International. 84-12B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:643707